Process of treating cement-kiln gases.



H. BLUMLNBERG, JR. PROCESS OF TREAIH'NG CEMENT KKLN GASES.

' APPLICATION FILED APR. 24. 1918, 1,296,465.

Patent-ed Mar. 4, 1919.

luvzuran HENRYBLUMENBERG JR. j QM "f .41

Ar-r'rs.

UNITED STATES PATENT OFFICE,

HENRY BLUMEN'BERG. JR, OF 030 GRANDE, CALIFORNIA, ASSIGNOR TO CHEMICAL CONSTRUCTION COMPANY, 0? LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA.

IPR-OCESS OF TREfiTING QEHENT-KILN GASES.

Application filed April 24, 1915? To all when: it may concrwz:

Be it known ihat l, HENRY llnonnnnnno, Jr.. a citizen of the United, States, residing at ()ro (irnndc. in the county of San Ben nardino and State of California, have invented new and useful Improvements in lroreeucs of Treating (,ittllltllllklilll! Gases, of which the following is a specification.

My invention rclnics to a [mucosa of ro rovering potassium compounds from the waste of rrincnt kilns, metallurgical furnaces and the like.

Potash, at the present time, may be 01 rained as a lily-product of Portland cement: Potassium rontaining raw materials Whirh arcotherwlse suitable for making cement are fed into the cement kilns Where the high irnnierature volatilizcs the potassium in the form of potassium oxid K 0, which is can ricd oil" in the Waste games. Various methods and (illVli'QS are used for the .extrurtitni and rcrovnry of the potassium oxid from the aste gases. In several of my copending' applications, I have desrri bed apparatus and methods for the extraction of' the potaseium oxitl from the waste gases, which briefly eonsist in rllerliing the velocity of the gases by cooling the Human thereby prsmipitating the larger portion of the cement dust retried therein and contacting the gases at a considerably lower temperature and free of the major portion of its solid contents, with a liquid or magn'ui having an affinity for carbon dioxid and potassium oxid rarried by the when. ,Vhiln a substantially complete rcrorrry of all potassium oxids may be oh? tainrd by those processes and apparatus, it is essential that, the gases be caused to con tact with the liquid or magma just referred to for a uutlirieut length of time for a complete recovery of the potassium oxirl.

It in an object of the premnt invention to simplify the method of extracting potausium oxitl and redure the time factor: whereby greater volumes of gases may b tront ml.

Another object of this invention in to utilize the great qunntitim of rarbon dioxid rarried by these gases in the production of u rommer iul article.

My invention roneists in the steps of the prorrse hereinafter lnurribml and chimed in the arconipnnying drawings which form a pm; of thin ope: ification. I hnveilius- Specification of Letters Patent.

Patented Mar. 4, 1919.

Serial No. 230,577.

trated diagrammatically an apparatus suitable for carrying out my process.

Referring to the drawmgs, 10 indicates the upper end of a rotary cement kiln communicating with a series of dust collecting rl'ianlbers 11 provided with bafile Walls 12. 13 designates evaporating pans forming the top of the dust collecting chambers 11. 14

a battle tower provided with suitable bafflee l5. 16 is a pump for rirrulating a liquid from tank 17 through pipe 18 to a spraying nozzle 19 at the upper end of the battle tower let. A return pipe '20 leads from the bottom of the batlle tower 14 to the pump 16. A pipe 21 leads from the pump 18 to the evaporating tanks 13. the halite tower let to a carbonation tank 23. The conduit 22 terminates in a veil of perforated pipe 24 disposed at the bottom of tank 23. 25 is a valve controlled outlet pipe lending fron tank 23.

In the operation of my process; the hot Waste gases coming from the cement kiln 10 pass through the dust collecting and cooling chamber 13 Where the velority of the gases is checked due to the ('Ontraction of the volume through the cooling of the gases and the greater ortion of the cement dust is deposited. T gases pass next through the baffle tower l4 and the same are brought in rontact with a liquid or magma sprayed from the spraying nozzle 19. The liquid used inthe ballie tower may be water, an alkaline aqueous mixture containing sodium potassium aluminum r-iilicatcs made by fusmg feldspar and sodium salt, sodium chloricl, an auueous mixture of a sulfate of an alkali metalor alkaline earth metal, or sodium.

nitrate, and the like. The same is repeatedly eirrulated through the bafiie tower 14 until sufiiriently enriched with a potassium compound and calcium carbonate, and, is then pumped to the evaporating pans 13. The leaving the ballle tower 14 contain carbon dioxid, nitrogen, small quantities of oxygen and carbon inonoxid and the morninifig portion of the potassium oxid. The same now pass through the carbonation tank which is filled with a solution of sodium carbonate. The carbon dioxid will combine with the sorlilnn carbonate to form sodium birarbonatc and the remaining portion 3f the potassium oxid will be recovered in tne A conduit 22 leads from form of potassium bicarbonate. The carbonate solutions in tank 23 are then conducted to suitable concentrating tanks, (not shown) where the sodium bicarbonate is separated from the potassium bicarbonate by crystallization. The solubility of the otassium bicarbonate as compared with t at of the sodium bicarbonateis as 11 to 4.

The process just described not only recovers all the potassium oxid carried in the hot gases in a rapid manner without the necessity of providing high bafiie towers or a series of them, and at the same time utilizes the carbon dioxid hitherto allowed to go to Waste. At the cement mill at Oro Grands, California, eighty tons of carbon dioxid are liberated every twenty-four hours with one ton of K,,O and about ten tons of cement dust. Making allowance for the carbonation of the cement dust in the apparatus, there is still about seventy tons of carbon dioxid in the gases While it is true that in the ammonia process of making sodium carbonate, sodium bicarbonate is formed as an intermediate product which is subsequently calcined to form the soda ash of commerce, the cost of soda ash and bicarbonate of soda in the market is about the same. However, two thousand pounds of soda ash converted into sodium bicarbonate yields about twenty nine hundred pounds, thus increasing the value of the soda ash almost 50%, less the operating expenses.

In lace of the soda ash, lead oxid may be used in the carbonation tank 23, which may be converted into basic lead carbonate or white lead or any other compound may be used having an aflinity for carbon dioxid and which, when carbonated, yields :1 marketable product.

I claim:

1. A process of recovering potassium compounds from the hot gases of cement kilns and the like, comprising cooling said gases and precipitating the larger portion of the cement dust, treating said gases with a suitable liquid for extracting the remainder of the cement dust and a portion of the potassium compounds, and passing said gases through a solution of sodium carbonate, where the remainder of the otassium-compounds is absorbed, thereby orming sodium bicarbonate and potassium bicarbonate, and separating the potassium bicarbonate from the sodium bicarbonate.

2. A process of recovering potassium compounds from the hot gases of cement kilns and the like, rbmprising cooling said gases and precipitating the larger portion of the cement dust, treatingsaid gases with a suitable liquid for extracting the remainder of the cement dust and a portion of the potassium compounds, and passing said gases through an aqueous mixture containing a compound having an aflinity for carbon dioxid, where the remainder of the potassium compounds is absorbed, thereby forming a carbonate with the base of sai cor pound and potassium bicarbonate, and separating the potassium bicarbonate from the mixture.

In testimony whereof I have signed my name to this specification.

HENRY B LUMENBERG. JR. 

